Long-term immune dysfunction after radiotherapy to the head and neck area

• Published in: International immunopharmacology Vol. 3; no. 8; pp. 1093 - 1104
• Main Authors: Verastegui, Emma L, Morales, Rocio B, Barrera-Franco, Jose L, Poitevin, Adela C, Hadden, John
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2003
• Subjects: Adult; Central Nervous System Neoplasms - immunology; Central Nervous System Neoplasms - radiotherapy; Female; Follow-Up Studies; Head and neck cancer; Head and Neck Neoplasms - immunology; Head and Neck Neoplasms - radiotherapy; Humans; Immune dysfunction; Immunologic Memory - immunology; Immunologic Memory - radiation effects; Lymphocyte Count; Lymphopenia; Lymphopenia - etiology; Lymphopenia - immunology; Male; Middle Aged; Neoplasms, Squamous Cell - immunology; Neoplasms, Squamous Cell - radiotherapy; Prospective Studies; Radiotherapy; Radiotherapy - adverse effects; T-cell subsets; T-Lymphocyte Subsets - immunology; T-Lymphocyte Subsets - radiation effects; Time Factors; Uterine Cervical Neoplasms - immunology; Uterine Cervical Neoplasms - radiotherapy; Head and neck cancer; Lymphopenia; Radiotherapy; Immune dysfunction; T-cell subsets
• ISSN: 1567-5769; 1878-1705
• DOI: 10.1016/S1567-5769(03)00013-4

Background: Hematological side effects are not generally expected due to radiotherapy involving limited radiation fields; however, patients with squamous cell carcinoma of the head and neck (SCCH&N) receiving radiation therapy frequently have chronic intraoral infections. Xerostomia has been implicated as a cause of it, but local or systemic immune alterations are not usually considered. Methods: With the purpose of evaluating the impact of radiotherapy treatment to different anatomic sites on immune function, 70 patients were evaluated during and after radiotherapy: 50 cases with SCCH&N, 10 with squamous cell carcinoma of the uterine cervix (SCCUC) and 10 patients with central nervous system tumors (CNS). We analyzed lymphocyte counts and T-cell subsets, and over time, their association with the presence of intracellular infections and disease-free survival. Results: Severe lymphopenia was observed in patients with SCCUC and SCCH&N by the fifth week of treatment. Patients with CNS tumors developed mild lymphopenia. In patients with SCCH&N and UC, lower counts were seen in B cells and total T lymphocyte counts including both CD4 + and CD8 + cell subsets. The patients with SCCUC recovered lymphocyte counts by the 24th month but T-cell subsets lagged behind. None of the SCCH&N patients had fully recovered by 60 months of follow-up. Recurrence correlates with low lymphocyte counts. Discussion: This work highlights the vulnerability of the head and neck area to the impact of radiotherapy as a reservoir of lymphoid cells. The possibility of recovery as a consequence of thymopoiesis and/or peripheral clonal expansion may limit the antigen-specific recognition of relevant tumor or microbial antigens and cause significant and prolonged immune alterations that may impact long-term survival.